All posts tagged weather

We have just had record rain in November in Dunedin, we have had a lot of fog and drizzle so far this month, it is pouring with rain now, so the hope we might eventually get some nice weather is welcome.

Our summer was shaping up as a very dry one too, until the ex-tropical cyclones brought in some heavy rains.

Apart from noticeably nice weather in Dunedin there have also been significantly different growing patterns, with things like tomatoes and grapes doing much better than usual.

Note that this is a weather record for three months, but it inevitable raises questions about how the climate could be changing overall. Unseasonably warm weather in the Arctic Circle, which pushed cold air down onto the US and Europe, have also been unusual.

We have had an extremely good run of good weather in Dunedin, and around most if not all of the country.

Apart from some morning harbour fog and some occasional cloud we have had an extended run of fine mild weather for nearly two weeks.

Temperatures have been maxxing in the low to mid twenties every day – unless exerting yourself these are very comfortable temperatures. I think that 20-24 is the optimum comfort zone, and that’s what we have been in, with enough night time cooling to be comfortable for sleep time as well.

In Central Otago the temperatures have been higher with November records being broken, enough to cause complaints. Cromwell must be up to day 12 or 13 days of 25+ temperatures, with some highs in the low to mid thirties. A few days of that can wear you down.

A few days of weather like this is not unusual, but two weeks is abnormal, especially for November which is often quite unsettled. Here it can swing from warm nor’westers to plummets and hilltop snow via sou’westers.

The Dunedin forecast promises more, with 23-27 highs and dry for the next week except for 18 and rain on Wednesday. Things are drying but aren’t too bad yet, but that rain will be welcome – if we get it.

A thing you learn in Dunedin is to appreciate and make the most of good weather, because variability and swings are the norm.

So this extended run of very nice early summer weather is great bonus.

It’s cold and a bit windy and there’s a light smattering of snow here in Dunedin this morning. There’s a bit more snow at higher altitudes, but traffic is still flowing through Roslyn (at about 150 m).

There’s likely to be a bit more in the higher suburbs, but so far it doesn’t seem to be major.

So far news reports have tend towards over the top and scaremongering. Last night the RNZ description of the South Island on Tuesday was nothing like what I saw around Otago (via webcams).

1 News also implied widespread snow and of course managed to find some in the middle of the South Island, but in a report on Queenstown suggesting snow had hit there they showed that it hadn’t settled in most of the town, and there was only a light smattering on the mountains.

They had someone reporting with snow falling – on the Mount Hutt Skifield road. They can’t have found any at altitudes that most people live.

This isn’t an Antarctic blast so there isn’t major polar energy coming in off the ice caps, instead a large high over Australia is helping scoop up cold air from over the Southern Ocean area – this is going to merge with sub-tropical rain (coming in as a wet cold easterly) around Wednesday, Thursday and Friday creating both heavy rain and heavy snow (rain heavy at sea level falling as heavy snow above 200 or 300m).

Sea level snow isn’t highly likely at this stage – at least not settling or falling in large amounts.

But it is possible that we may see some flurries reaching low levels, or sea level, around Southland, Otago and parts of Canterbury for a time (especially overnight tonight and early Wednesday morning).

Remember this isn’t a major storm and isn’t an Antarctic blast, even if there will be some severe weather – we usually need a few moving parts all lined up in the right places to get snow into our biggest centres at heavy amounts or sea level. Dunedin is the highest candidate for snow out of the main centres for this event.

A cold front, followed by strong cold southerlies, has moved across the South Island today, and will sweep farther northwards over central New Zealand tonight and during Wednesday. Snow has already fallen to low levels in the South Island. Further snow showers are forecast through Wednesday and Thursday in southern and eastern areas, falling as low as 100 or 200 metres at times. Significant accumulations are likely at higher elevations, and especially the Kaikoura Ranges could see an extended period of snowfall.

In the lower and central North Island, snow could fall as low as 400 or 500 metres.

Additionally, a low is forecast to develop east of central New Zealand during Wednesday and deepen rapidly on Thursday, bringing heavy rain and gale south to southeast winds to the upper South Island and the lower North Island.

So we are getting some knarly winter weather in the middle of winter, but so far it doesn’t seem out of the ordinary.

Care certainly needs to be taken on roads, not just from snow if there’s any there but also from ice which is more dangerous. Normal winter precautions need to be taken.

I’ll check the street when it gets light. I may delay going to work but unless something changes significantly I should get out by mid morning.

The weather forecast is for a bit of a southerly over the next few days in what is usually about the coldest part of winter. It could end up being a but more sustained and snowy than usual. That happens sometimes.

Not that headline writers from Auckland would understand that. NZ Herald:

The country is preparing for its worst winter storm of the year with rain, snow and gales set to batter much of New Zealand.

Snow is expected to fall to very low levels in the south of the country with potentially damaging gales, torrential rain and snow lashing the country from Gisborne south.

The Milford Rd is closing at 5pm with significant snow forecast to about 500m by tomorrow morning.

This morning’s forecast is for snow to 200 metres in the South Island. That’s not a big deal, it’s common and doesn’t mean it will settle at that altitude.

Over the next few days it could snow to sea level and settle for a day or two. Snow tends to be fickle and regional – it sounds like inland South Island and Canterbury may cop the worst but that’s uncertain.

A problem with the “four days of hell” headlines is that most people will dismiss it as Auckland bull and go about their lives as per normal for this time of year.

Last week’s forecast snow didn’t happen in most places. That’s more common than actually getting snow.

It could be a bit cool at home, there is a scheduled power cut today. But I’ll go to work as usual, and will probably get home again tonight. I have never been unable to get home because of snow. If it does settle it is more likely to come in the night, and a day or two every year or two I get to have a late start, usually getting out by mid morning.

Every few years we get a day or two where we get ‘snowed in” for a day – usually not badly but it is simply unwise to travel unless you really need to. Things can go on a hold for a day without much problem.

This winter southerly could be worse, it sounds likely to be in some areas, but Metservice is still only forecasting sleet in Dunedin, which looks nice but doesn’t cause any problems.

Some of the highest hill suburbs may get a dump and higher roads are likely to be affected – media will find a road somewhere with some snow on it.

But we will carry on as usual for winter and see what happens without getting too excited about it.

A cold front will sweep northwards across the South Island during Tuesday. In the wake of this front, snow is forecast to fall in the south and east, with further snow overnight Tuesday and on Wednesday as very cold air aloft moves over the South Island.

Snow is likely to fall as low as 200 or 300 metres at times from Tuesday until Thursday, with significant accumulations for higher elevations. 20 to 30cm, possibly even more, could accumulate on Otago and Canterbury high country stations. This will affect many higher roads, and could cause problems for livestock from Southland to Banks Peninsula.

This Watch is for the likelihood of significant snow accumulations below 500 metres in the following areas…

Southland and Fiordland: From early Tuesday morning till Wednesday afternoon.

Otago: For a time Tuesday morning, and again Tuesday night till Wednesday evening.

People in these areas are strongly advised to stay up to date with the latest forecasts and warnings, as this event unfolds. Road snowfalls warnings will be in effect and warnings for heavy snow could be issued at a later stage.

After several days of dire forecasts it looks like being a snow day in Dunedin today. There’s a very light smattering of snow on the ground and it is current snowing gently.

The forecast is still mixed – “Sleety rain, snow flurries about the hills. Cold southeast” – with light precipitation off and on through the day. It is currently 0.8 degrees in Dunedin (MetService), and on the University weather site it has risen to 1.0 degrees from a low of 0.3 but there is no sign of snow on their webcam (close to sea level).

The Roslyn webcams give a good indication of the state of the city, in the hill suburbs at least. One view:

So it is currently snowing there too with a light covering of snow on the road but many peoeple would drive on that.

Roslyn is about 150 metres compared to 100 metres where I live which can make a difference.

The Northern Motorway will either be closed or is likely to be causing problems for some motorists.

I won’t know what this means for my day until it gets light in a couple of hours. The snow could have increased by then, or it could have stopped and melted back. So I may or may not get a snow day at home, olr a part snow day, with light overnight snow it is often ok to drive by mid morning.

We will see what daylight gives us. But going by the current Highgate pics it looks like more snow for a while anyway:

Increasing but still passable for the foolhardy – it’s silly to be driving in these conditions especially as it is deteriorating.

Temperatures have dropped slightly in the last half hour but that’s common just before dawn.

But this doesn’t give me a day off work. I do most of my work by phone and online and wee are prepared for the occasional bit of weather, so I just communicate from a different location, and have important work that needs to be done today.

UPDATE: that flurry has already passed by, and there has been more traffic in Roslyn.

Another update:

It was a short snowfall that is clearing quickly off the roads already. This is fairly typical. Looks like work on time unless another flurry comes through.

Schools are closed until 10.00 am and hill suburbs are likely to be risky.

It looks like we are in for the first decent cold spell for the winter. It has begun in inland South Island with a big dump of snow on the hills and a bit to lower levels, but there is no sign of any snow in Dunedin this morning, and the forecast now says the snow mightn’t come until tomorrow.

Following record high overall temperatures for the first months of this year May has begun with unusually high temperatures for this time of year.

And according to the Metservice this looks likely to continue, with highs of 19, 22, 17, 17 forecast in Dunedin over the next four days, dropping t 13-15 over the next week, still not particularly cool for May. The average high in May for Dunedin is 12.7 degrees.

The lows forecast over the next ten days range from 8-11 degrees.

The lowest low over the past month has been 6, which isn’t bad for an overnight temperature.

No sign of any pre-wintry blasts from the Antarctic.

This isn’t a complaint about a continuation of a very good run of weather this year, it’s been great and we’ve had the best growing conditions I can remember here, even though rainfall has been relatively low and infrequent.

Long may the balmy weather continue – as long as it doesn’t creep south and melt an ice shelf or two.

When scientists talk about climate change, there’s one word they use time and time again: “non-linear”.

Most people think of global warming as an incremental thing. Alas, most people are wrong. The climate is a very complex system, and complex systems can change in non-linear ways.

We cannot count on the average global temperature rising steadily but slowly as we pump more and more greenhouse gases into the atmosphere. It may do that — but there may also be a sudden jump in the average global temperature that lands you in a world of hurt. That may be happening now.

“We are moving into uncharted territory with frightening speed,” said Michel Jarraud, secretary-general of the World Meteorological Organization, last November. He was referring to the fact that the warming is accelerating in an unprecedented way.

2014 was the hottest year ever, until 2015 beat it by a wide margin. 2016 may beat that record by an even wider margin. It was the hottest January ever and the average global temperature in February was a full fifth of a Celcius degree higher than January.

The “average global temperature” is an average of all the temperatures over seas and land in both summer and winter hemispheres. It is normally very stable, changing no more than a few hundredths of a degree from year to year.

But March was not only hotter than February. It was hotter by an even wider margin than February was over January. Indeed, each of the past 11 months has beaten the highest previously recorded average temperature for that month.

Certainly we have experienced a noticeably nice and warmer than usual summer and autumn in Dunedin. Sure, this is partly due to having El Nino and it’s going to cool down next week (according to the current forecast) but it has been abnormally settled and warm.

But the overall trends are what matters with climate, and trends are tending towards alarming. Tipping points and feedback loops have been predicted, they could be happening.

The weather could cycle back to cooler, but it could get better (or worse depending on how you view things).

But I think there is at least serious cause for concern. The above are not isolated reports.

Some people try to explain blame it on El Niño, a periodical rise in the ocean surface temperature in the eastern Pacific that moves the rainfall patterns around worldwide, causing droughts here and floods there. But El Niño is a local rise in temperature, it does not normally affect the average global temperature much.

As for the frightening acceleration in the warming in the past three months, that has no precedent in any El Niño year, or indeed in any previous year. It could be some random short-term fluctuation in average global temperature, but coming on top of the record warming of 2014 and 2015 it feels a lot more like part of a trend.

Could this be non-linear change, an abrupt and irreversible change in the climate? Yes. And if it is, how far will it go before it stabilizes again at some higher average global temperature? Nobody knows.

A new study in the journal Nature has found that 80% of the U.S. population lives in counties experiencing more pleasant weather than they did 40 years ago.

“Virtually all Americans are now experiencing the much milder winters that they typically prefer, and these mild winters have not been offset by markedly more uncomfortable summers or other negative changes.”

By the end of the century, however, the study predicts the pleasant weather trend to reverse as summers heat up to uncomfortable temperatures.

If greenhouse gas emissions continue unchecked, 88% of the current population will live in areas where the weather is less pleasant than it was before.

Extensive aerial surveys and dives have revealed that 93 percent of the world’s largest reef has been devastated by coral bleaching. The culprit has been record-warm water driven by El Niño and climate change that has cooked the life out of corals.

Etc.

And when what we are experiencing symptoms of what could be an earth-wide problem it’s difficult to ignore.